Swimming With Bold-Faced Creatures

This is the time of year to face fears of riptides, jellyfish and sharks.

But for James Cameron, the “Titanic” and “Avatar” director, who went down seven miles in one of the deepest parts of the ocean, fear of the sea is never an option.

“What scared me more was being on the ‘Tonight’ show just now,” he said outside the American Museum of Natural History on Monday, where “Deepsea Challenge 3D,” a National Geographic documentary about his adventure, was having its premiere. “If something goes wrong on a dive it can be fixed, but if I screw up on TV I have to live with it the rest of my life.”

He was greeted like a conquering hero for commissioning and piloting his submersible vessel, which looked like a lime-green metal coffin on display outside.

“What does it mean when the thrusters fail?” a rapt Charlie Rose asked him as they descended in an elevator only slightly less claustrophobic than a submarine.

“It means you can’t explore anymore,” Mr. Cameron said.

During cocktail hour, guests could explore one another, along with dramatic marine-life replicas in the Hall of Biodiversity. Bryant Gumbel, Regis Philbin and William J. Bratton, New York’s police commissioner, moved among schools of biologists and explorers.

“What kind of water is that?” one guest asked a waiter.

“Regular water,” came the reply, “as regular as can be.”

Later, under the 94-foot blue whale, film loops of bubbles surrounded the V.I.P. audience waiting for the movie. Deep-sea thuds and gurgles lent an ominous tone.

“I’m not scared of the ocean,” said Fisher Stevens, the actor and a producer of “The Cove,” the 2010 Oscar-winning dolphin fishing documentary, who said he had been rescued several times while scuba diving. “And I’m not scared of sharks unless they’re agents.”

Rosanna Scotto of “Good Day New York” said she is scared of swimming in any water that isn’t chlorinated. “I also have a fear of getting my hair wet,” she added.

Her co-host, Greg Kelly, had another fear. “Dying alone,” he said.

That seemed a possibility in the film, which pitted Mr. Cameron against technical failures and rough seas. After watching him star in the story of his obsession, controlling his submersible on the ocean floor with the composure of an astronaut and the glee of a video-game-playing child, the audience took off 3-D glasses to come up for air and a reception.

Amid displays of Rolex watches, the sponsor of the project and event, the crowd fed on all-vegan canapés, including vegetarian sushi, for dinner.

Darren Aronofsky, whose latest movie, “Noah,” tested the waters of wet-actor endurance, circulated. So did David Blaine, the magician who once entombed himself under a three-ton water tank. After posing with Mr. Cameron and other fans, Larry David volunteered that he never goes into the water on Martha’s Vineyard.

“In fact, I spend the summer avoiding the beach as much as possible,” he said.

And what scares Sylvia Earle, the renowned marine biologist and explorer?

“Driving in Oakland traffic on the way to my submarine,” she said.

Good thing she doesn’t keep it in Montauk.

A version of this article appears in print on , on Page E6 of the New York edition with the headline: Swimming With Bold-Faced Creatures. Order Reprints | Today’s Paper | Subscribe